Refrigerant compositions including hexafluoropropane and a hydrofluorocarbon

ABSTRACT

This invention relates to compositions of a hexafluoropropane and a hydrofluorocarbon, with the hydrofluorocarbon being hexafluoropropane, pentafluoropropane, tetrafluoropropane, trifluoropropane, difluoropropane, fluoropropane, or (CF 3 ) 2  CHCH 3 . The compositions, which may be azeotropic or azeotrope-like, may be used as refrigerants, cleaning agents, expansion agents for polyolefins and polyurethanes, aerosol propellants, refrigerants, heat transfer media, gaseous dielectrics, fire extinguishing agents, power cycle working fluids, polymerization media, particulate removal fluids, carrier fluids, buffing abrasive agents or displacement drying agents.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of pending U.S. patentapplication Ser. No. 08/039,563, filed Mar. 29, 1993 now abandoned.

FIELD OF THE INVENTION

This invention relates to compositions of mixture of hydrofluorocarbons.These compositions are useful as cleaning agents, expansion agents forpolyolefins and polyurethanes, aerosol propellants, refrigerants, heattransfer media, gaseous dielectrics, fire extinguishing agents, powercycle working fluids, polymerization media, particulate removal fluids,carrier fluids, buffing abrasive agents, and displacement drying agents.

BACKGROUND OF THE INVENTION

Fluorinated hydrocarbons have many uses, one of which is as arefrigerant. Such refrigerants include dichlorodifluoromethane (CFC-12)and chlorodifluoromethane (HCFC-22).

In recent years it has been pointed out that certain kinds offluorinated hydrocarbon refrigerants released into the atmosphere mayadversely affect the stratospheric ozone layer. Although thisproposition has not yet been completely established, there is a movementtoward the control of the use and the production of certainchlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) under aninternational agreement.

Accordingly, there is a demand for the development of refrigerants thathave a lower ozone depletion potential than existing refrigerants whilestill achieving an acceptable performance in refrigeration applications.Hydrofluorocarbons (HFCs) have been suggested as replacements for CFCsand HCFCs since HFCs have no chlorine and therefore have zero ozonedepletion potential.

In refrigeration applications, a refrigerant is often lost duringoperation through leaks in shaft seals, hose connections, solderedjoints and broken lines. In addition, the refrigerant may be released tothe atmosphere during maintenance procedures on refrigeration equipment.If the refrigerant is not a pure component or an azeotropic orazeotrope-like composition, the refrigerant composition may change whenleaked or discharged to the atmosphere from the refrigeration equipment,which may cause the refrigerant to become flammable or to have poorrefrigeration performance.

Accordingly, it is desirable to use as a refrigerant a singlefluorinated hydrocarbon or an azeotropic or azeotrope-like compositionthat includes one or more fluorinated hydrocarbons.

Fluorinated hydrocarbons may also be used as a cleaning agent or solventto clean, for example, electronic circuit boards. It is desirable thatthe cleaning agents be azeotropic or azeotrope-like because in vapordegreasing operations the cleaning agent is generally redistilled andreused for final rinse cleaning.

Azeotropic or azeotrope-like compositions that include a fluorinatedhydrocarbon are also useful as blowing agents in the manufacture ofclosed-cell polyurethane, phenolic and thermoplastic foams, aspropellants in aerosols, as heat transfer media, gaseous dielectrics,fire extinguishing agents, power cycle working fluids such as for heatpumps, inert media for polymerization reactions, fluids for removingparticulates from metal surfaces, as carrier fluids that may be used,for example, to place a fine film of lubricant on metal parts, asbuffing abrasive agents to remove buffing abrasive compounds frompolished surfaces such as metal, as displacement drying agents forremoving water, such as from jewelry or metal parts, as resistdevelopers in conventional circuit manufacturing techniques includingchlorine-type developing agents, or as strippers for photoresists whenused with, for example, a chlorohydrocarbon such as1,1,1-trichloroethane or trichloroethylene.

SUMMARY OF THE INVENTION

The present invention relates to the discovery of refrigerantcompositions of hexafluoropropane and a hydrofluorocarbon, with thehydrofluorocarbon being hexafluoropropane, pentafluoropropane,tetrafluoropropane, trifluoropropane, difluoropropane, fluoropropane, orHFC-356mmz. These compositions are also useful as cleaning agents,expansion agents for polyolefins and polyurethanes, aerosol propellants,heat transfer media, gaseous dielectrics, fire extinguishing agents,power cycle working fluids, polymerization media, particulate removalfluids, carrier fluids, buffing abrasive agents, and displacement dryingagents. Further, the invention relates to the discovery of binaryazeotropic or azeotrope-like compositions comprising effective amountsof hexafluoropropane and hexafluoropropane, pentafluoropropane,tetrafluoropropane, trifluoropropane, difluoropropane, fluoropropane, orHFC-356mmz to form an azeotropic or azeotrope-like composition.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236ca and HFC-236fa at 25° C.;

FIG. 2 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236ca and HFC-245eb at 25° C.;

FIG. 3 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236ca and HFC-245fa at 25° C.;

FIG. 4 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236ca and HFC-254eb at 25° C.;

FIG. 5 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236ca and HFC-263ca at 25° C.;

FIG. 6 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236ca and HFC-263fb at 25° C.;

FIG. 7 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236ca and HFC-272ca at 25° C.;

FIG. 8 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236ca and HFC-272fb at 25° C.;

FIG. 9 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236ca and HFC-281ea at 25° C.;

FIG. 10 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236ca and HFC-356mmz at 25° C.;

FIG. 11 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236cb and HFC-236ea at 25° C.;

FIG. 12 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236cb and HFC-236fa at 25° C.;

FIG. 13 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236cb and HFC-245fa at 25° C.;

FIG. 14 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236cb and HFC-254cb at 25° C.;

FIG. 15 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236cb and HFC-254eb at 25° C.;

FIG. 16 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236cb and HFC-263fb at 25° C.;

FIG. 17 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236cb and HFC-272ca at 25° C.;

FIG. 18 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236cb and HFC-281ea at 25° C.;

FIG. 19 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236cb and HFC-281fa at 25° C.;

FIG. 20 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236ea and HFC-236fa at 25° C.;

FIG. 21 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236ea and HFC-245cb at 25° C.;

FIG. 22 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236ea and HFC-263fb at 25° C.;

FIG. 23 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236ea and HFC-272ca at 25° C.;

FIG. 24 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236ea and HFC-272fb at 25° C.;

FIG. 25 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236ea and HFC-281ea at 25° C.;

FIG. 26 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236ea and HFC-281fa at 25° C.;

FIG. 27 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236fa and HFC-245ca at 25° C.;

FIG. 28 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236fa and HFC-245eb at 25° C.;

FIG. 29 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236fa and HFC-254ca at 25° C.;

FIG. 30 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236fa and HFC-254cb at 25° C.;

FIG. 31 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236fa and HFC-254eb at 25° C.;

FIG. 32 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236fa and HFC-272ca at 25° C.;

FIG. 33 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236fa and HFC-272ea at 25° C.;

FIG. 34 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236fa and HFC-281ea at 25° C.; and

FIG. 35 is a graph of the vapor/liquid equilibrium curve for mixtures ofHFC-236fa and HFC-281fa at 25° C.

DETAILED DESCRIPTION

The present invention relates to the following compositions:

(a) 1,1,2,2,3,3-hexafluoropropane (HFC-236ca) and1,1,1,3,3,3-hexafluoropropane (HFC-236fa), 1,1,1,2,3-pentafluoropropane(HFC-45eb), 1,1,1,3,3-pentafluoropropane (HFC-245fa),1,1,1,2-tetrafluoropropane (HFC-254eb), 1,2,2-trifluoropropane(HFC-263ca), 1,1,1-trifluoropropane (HFC-263fb), 2,2-difluoropropane(HFC-272ca), 1,1-difluoropropane (HFC-272fb), 2-fluoropropane(HFC-281ea) or (CF₃)₂ CHCH₃ (HFC-356mmz);

(b) 1,1,1,2,2,3-hexafluoropropane (HFC-236cb) and1,1,2,3,3,3-hexafluoropropane (HFC-236ea), HFC-236fa, HFC-245fa,1,1,2,2-tetrafluoropropane (HFC-254cb), HFC-254eb, HFC-263fb, HFC-272ca,HFC-272fb, HFC-281ea or 1-fluoropropane (HFC-281fa);

(c) HFC-236ea and HFC-236fa, 1,1,1,2,2-pentafluoropropane (HFC-245cb),HFC-263fb, HFC-272ca, HFC-272fb, HFC-281ea or HFC-281fa; or

(d) HFC-236fa and 1,1,2,2,3-pentafluoropropane (HFC-245ca), HFC-245eb,1,2,2,3-tetrafluoropropane (HFC-254ca), HFC-254cb, HFC-254eb, HFC-72ca,HFC-272ea, HFC-281ea or HFC-281fa.

1-99 wt. % of each of the components of the compositions can be used asrefrigerants. Further, the present invention also relates to thediscovery of azeotropic or azeotrope-like compositions of effectiveamounts of each of the above mixtures to form an azeotropic orazeotrope-like composition.

By "azeotropic" composition is meant a constant boiling liquid admixtureof two or more substances that behaves as a single substance. One way tocharacterize an azeotropic composition is that the vapor produced bypartial evaporation or distillation of the liquid has the samecomposition as the liquid from which it was evaporated or distilled,that is, the admixture distills/refluxes without compositional change.Constant boiling compositions are characterized as azeotropic becausethey exhibit either a maximum or minimum boiling point, as compared withthat of the non-azeotropic mixtures of the same components.

By "azeotrope-like" composition is meant a constant boiling, orsubstantially constant boiling, liquid admixture of two or moresubstances that behaves as a single substance. One way to characterizean azeotrope-like composition is that the vapor produced by partialevaporation or distillation of the liquid has substantially the samecomposition as the liquid from which it was evaporated or distilled,that is, the admixture distills/refluxes without substantial compositionchange.

It is recognized in the art that a composition is azeotrope-like if,after 50 weight percent of the composition is removed such as byevaporation or boiling off, the difference in vapor pressure between theoriginal composition and the composition remaining after 50 weightpercent of the original composition has been removed is less than 10percent, when measured in absolute units. By absolute units, it is meantmeasurements of pressure and, for example, psia, atmospheres, bars,torr, dynes per square centimeter, millimeters of mercury, inches ofwater and other equivalent terms well known in the art. If an azeotropeis present, there is no difference in vapor pressure between theoriginal composition and the composition remaining after 50 weightpercent of the original composition has been removed.

Therefore, included in this invention are compositions of effectiveamounts of

(a) 1,1,2,2,3,3-hexafluoropropane (HFC-236ca) and1,1,1,3,3,3-hexafluoropropane (HFC-236fa), 1,1,1,2,3-pentafluoropropane(HFC-245eb), 1,1,1,3,3-pentafluoropropane (HFC-245fa),1,1,1,2-tetrafluoropropane (HFC-254eb), 1,2,2-trifluoropropane(HFC-263ca), 1,1,1-trifluoropropane (HFC-263fb), 2,2-difluoropropane(HFC-272ca), 1,1-difluoropropane (HFC-272fb), 2-fluoropropane(HFC-281ea) or (CF3)2CHCH₃ (HFC-356mmz);

(b) 1,1,1,2,2,3-hexafluoropropane (HFC-236cb) and1,1,2,3,3,3-hexafluoropropane (HFC-236ea), HFC-236fa, HFC-245fa,1,1,2,2-tetrafluoropropane (HFC-254cb), HFC-254eb, HFC-263fb, HFC-272ca,HFC-272fb, HFC-281ea or HFC-281fa;

(c) HFC-236ea and HFC-236fa, HFC-245cb, HFC-263fb, HFC-272ca, HFC-272fb,HFC-281ea or HFC-281fa; or

(d) HFC-236fa and HFC-245ca, HFC-245eb, HFC-254ca, HFC-254cb, HFC-254eb,HFC-272ca, HFC-272ea, HFC-281ea or HFC-281fa;

such that after 50 weight percent of an original composition isevaporated or boiled off to produce a remaining composition, thedifference in the vapor pressure between the original composition andthe remaining composition is 10 percent or less.

For compositions that are azeotropic, there is usually some range ofcompositions around the azeotrope point that, for a maximum boilingazeotrope, have boiling points at a particular pressure higher than thepure components of the composition at that pressure and have vaporpressures at a particular temperature lower than the pure components ofthe composition at that temperature, and that, for a minimum boilingazeotrope, have boiling points at a particular pressure lower than thepure components of the composition at that pressure and have vaporpressures at a particular temperature higher than the pure components ofthe composition at that temperature. Boiling temperatures and vaporpressures above or below that of the pure components are caused byunexpected intermolecular forces between and among the molecules of thecompositions, which can be a combination of repulsive and attractiveforces such as van der Waals forces and hydrogen bonding.

The range of compositions that have a maximum or minimum boiling pointat a particular pressure, or a maximum or minimum vapor pressure at aparticular temperature, may or may not be coextensive with the range ofcompositions that have a change in vapor pressure of less than about 10%when 50 weight percent of the composition is evaporated. In those caseswhere the range of compositions that have maximum or minimum boilingtemperatures at a particular pressure, or maximum or minimum vaporpressures at a particular temperature, are broader than the range ofcompositions that have a change in vapor pressure of less than about 10%when 50 weight percent of the composition is evaporated, the unexpectedintermolecular forces are nonetheless believed important in that therefrigerant compositions having those forces that are not substantiallyconstant boiling may exhibit unexpected increases in the capacity orefficiency versus the components of the refrigerant composition.

The components of the compositions of this invention have the followingvapor pressures at 25° C.

    ______________________________________                                        Components        Psia   kPa                                                  ______________________________________                                        HFC-236ca         24.9   172                                                  HFC-236cb         33.6   232                                                  HFC-236ea         29.8   206                                                  HFC-236fa         39.4   271                                                  HFC-245ca         14.2   98                                                   HFC-245cb         67.4   465                                                  HFC-245eb         16.9   117                                                  HFC-245fa         21.6   149                                                  HFC-254ca         13.7   95                                                   HFC-254cb         34.2   236                                                  HFC-254eb         34.8   240                                                  HFC-263ca         18.2   126                                                  HFC-263fb         54.0   372                                                  HFC-272ca         34.5   238                                                  HFC-272ea         20.8   143                                                  HFC-272fb         26.5   182                                                  HFC-281ea         47.1   325                                                  HFC-281fa         37.7   260                                                  HFC-356mmz        16.6   114                                                  ______________________________________                                    

Substantially constant boiling, azeotropic or azeotrope-likecompositions of this invention comprise the following (all compositionsare measured at 25° C.):

    ______________________________________                                                        WEIGHT                                                                        RANGES      PREFERRED                                         COMPONENTS      (wt. %/wt/%)                                                                              (wt. %/wt. %)                                     ______________________________________                                        HFC-236ca/HFC-236fa                                                                           1-99/1-99    1-80/20-99                                       HFC-236ca/HFC-245eb                                                                           1-99/1-99    1-85/15-99                                       HFC-236ca/HFC-245fa                                                                           1-99/1-99   20-99/1-80                                        HFC-236ca/HFC-254eb                                                                           1-99/1-99   40-99/1-60                                        HFC-236ca/HFC-263ca                                                                           1-99/1-99   20-99/1-80                                        HFC-236ca/HFC-263fb                                                                            1-62/38-99  1-62/38-99                                       HFC-236ca/HFC-272ca                                                                            1-81/19-99 20-81/19-80                                       HFC-236ca/HFC-272fb                                                                           1-99/1-99   30-99/1-70                                        HFC-236ca/HFC-281ea                                                                            1-78/22-99  1-78/22-99                                       HFC-236ca/HFC-356mmz                                                                          1-99/1-99   50-99/1-50                                        HFC-236cb/HFC-236ea                                                                           1-99/1-99   1-99/1-99                                         HFC-236cb/HFC-236fa                                                                           1-99/1-99   1-99/1-99                                         HFC-236cb/HFC-245fa                                                                           1-99/1-99   1-60/40-99                                        HFC-236cb/HFC-254cb                                                                           1-99/1-99   20-99/1-80                                        HFC-236cb/HFC-254eb                                                                           1-99/1-99   20-99/1-80                                        HFC-236cb/HFC-263fb                                                                           1-99/1-99   1-99/1-99                                         HFC-236cb/HFC-272ca                                                                           1-99/1-99   40-99/1-60                                        HFC-236cb/HFC-272fb                                                                           1-99/1-99   20-99/1-80                                        HFC-236cb/HFC-281ea                                                                           1-99/1-99   20-99/1-80                                        HFC-236cb/HFC-281fa                                                                           1-99/1-99   20-99/1-80                                        HFC-236ea/HFC-236fa                                                                           1-99/1-99   1-99/1-99                                         HFC-236ea/HFC-245cb                                                                            1-45/55-99  1-45/55-99                                       HFC-236ea/HFC-263fb                                                                            1-65/35-99  1-65/35-99                                       HFC-236ea/HFC-272ca                                                                           1-99/1-99   20-99/1-80                                        HFC-236ea/HFC-272fb                                                                           1-99/1-99   40-99/1-60                                        HFC-236ea/HFC-281ea                                                                            1-87/13-99 15-87/13-85                                       HFC-236ea/HFC-281fa                                                                           1-99/1-99   20-99/1-80                                        HFC-236fa/HFC-245ca                                                                           72-99/1-28  72-99/1-28                                        HFC-236fa/HFC-245eb                                                                           60-99/1-40  60-99/1-40                                        HFC-236fa/HFC-254ca                                                                           68-99/1-32  68-99/1-32                                        HFC-236fa/HFC-254cb                                                                           1-99.8/0.2-99                                                                             49-99.8/0.2-60                                    HFC-236fa/HFC-254eb                                                                           1-99/1-99   40-99/1-60                                        HFC-236fa/HFC-272ca                                                                           1-99/1-99   40-99/1-60                                        HFC-236fa/HFC-272ea                                                                           64-99/1-36  64-99/1-36                                        HFC-236fa/HFC-281ea                                                                           1-99/1-99   40-99/1-60                                        HFC-236fa/HFC-281fa                                                                           1-99/1-99   40-99/1-60                                        ______________________________________                                    

For purposes of this invention, "effective amount" is defined as theamount of each component of the inventive compositions which, whencombined, results in the formation of an azeotropic or azeotrope-likecomposition. This definition includes the amounts of each component,which amounts may vary depending on the pressure applied to thecomposition so long as the azeotropic or azeotrope-like compositionscontinue to exist at the different pressures, but with possibledifferent boiling points.

Therefore, effective amount includes the amounts, such as may beexpressed in weight percentages, of each component of the compositionsof the instant invention which form azeotropic or azeotrope-likecompositions at temperatures or pressures other than as describedherein.

For the purposes of this discussion, azeotropic or constant-boiling isintended to mean also essentially azeotropic or essentially-constantboiling. In other words, included within the meaning of these terms arenot only the true azeotropes described above, but also othercompositions containing the same components in different proportions,which are true azeotropes at other temperatures and pressures, as wellas those equivalent compositions which are part of the same azeotropicsystem and are azeotrope-like in their properties. As is well recognizedin this art, there is a range of compositions which contain the samecomponents as the azeotrope, which will not only exhibit essentiallyequivalent properties for refrigeration and other applications, butwhich will also exhibit essentially equivalent properties to the trueazeotropic composition in terms of constant boiling characteristics ortendency not to segregate or fractionate on boiling.

It is possible to characterize, in effect, a constant boiling admixturewhich may appear under many guises, depending upon the conditionschosen, by any of several criteria:

* The composition can be defined as an azeotrope of A, B, C (and D . . .) since the very term "azeotrope" is at once both definitive andlimitative, and requires that effective amounts of A, B, C (and D . . .) for this unique composition of matter which is a constant boilingcomposition.

* It is well known by those skilled in the art, that, at differentpressures, the composition of a given azeotrope will vary at least tosome degree, and changes in pressure will also change, at least to somedegree, the boiling point temperature. Thus, an azeotrope of A, B, C(and D . . . ) represents a unique type of relationship but with avariable composition which depends on temperature and/or pressure.Therefore, compositional ranges, rather than fixed compositions, areoften used to define azeotropes.

* The composition can be defined as a particular weight percentrelationship or mole percent relationship of A, B, C (and D . . . ),while recognizing that such specific values point out only oneparticular relationship and that in actuality, a series of suchrelationships, represented by A, B, C (and D . . . ) actually exist fora given azeotrope, varied by the influence of pressure.

* An azeotrope of A, B, C (and D . . . ) can be characterized bydefining the compositions as an azeotrope characterized by a boilingpoint at a given pressure, thus giving identifying characteristicswithout unduly limiting the scope of the invention by a specificnumerical composition, which is limited by and is only as accurate asthe analytical equipment available.

The azeotrope or azeotrope-like compositions of the present inventioncan be prepared by any convenient method including mixing or combiningthe desired amounts. A preferred method is to weigh the desiredcomponent amounts and thereafter combine them in an appropriatecontainer.

Specific examples illustrating the invention are given below. Unlessotherwise stated therein, all percentages are by weight. It is to beunderstood that these examples are merely illustrative and in no way areto be interpreted as limiting the scope of the invention.

EXAMPLE 1 Phase Study

A phase study shows the following compositions are azeotropic, all at25° C.

    ______________________________________                                                                Vapor Press.                                          Composition No.         psia (kPa)                                            ______________________________________                                        HFC-236ca/HFC-236fa                                                                              7.6/92.4 39.5   272                                        HFC-236ca/HFC-245eb                                                                              9.1/90.9 16.9   117                                        HFC-236ca/HFC-245fa                                                                             98.3/1.7  24.9   172                                        HFC-236ca/HFC-254eb                                                                             77.4/22.6 21.7   150                                        HFC-236ca/HFC-263ca                                                                             35.4/64.6 17.8   123                                        HFC-236ca/HFC-263fb                                                                             13.7/86.3 54.6   376                                        HFC-236ca/HFC-272ca                                                                             46.8/53.2 40.2   277                                        HFC-236ca/HFC-272fb                                                                             56.1/43.9 29.0   200                                        HFC-236ca/HFC-281ea                                                                             16.3/83.7 47.4   327                                        HFC-236ca/HFC-356mmz                                                                            78.1/21.9 25.8   178                                        HFC-236cb/HFC-236ea                                                                             36.7/63.3 27.6   190                                        HFC-236cb/HFC-236fa                                                                             28.2/71.8 41.7   288                                        HFC-236cb/HFC-245fa                                                                             25.6/74.4 20.5   141                                        HFC-236cb/HFC-254cb                                                                             52.1/47.9 28.8   199                                        HFC-236cb/HFC-254eb                                                                             39.0/61.0 35.2   243                                        HFC-236cb/HFC-263fb                                                                             19.0/81.0 55.0   379                                        HFC-236cb/HFC-272ca                                                                             58.2/41.8 41.3   285                                        HFC-236cb/HFC-272fb                                                                             45.0/55.0 26.1   180                                        HFC-236cb/HFC-281ea                                                                             39.1/60.9 48.9   337                                        HFC-236cb/HFC-281fa                                                                             56.1/43.9 40.4   279                                        HFC-236ea/HFC-236fa                                                                             17.6/82.4 41.4   285                                        HFC-236ea/HFC-245cb                                                                              3.7/96.3 67.6   466                                        HFC-236ea/HFC-263fb                                                                             20.0/80.0 56.2   387                                        HFC-236ea/HFC-272ca                                                                             50.0/50.0 41.7   288                                        HFC-236ea/HFC-272fb                                                                             75.0/25.0 31.0   214                                        HFC-236ea/HFC-281ea                                                                             33.9/66.1 48.7   336                                        HFC-236ea/HFC-281fa                                                                             44.8/55.2 39.9   275                                        HFC-236fa/HFC-245ca                                                                             98.0/2.0  39.5   272                                        HFC-236fa/HFC-245eb                                                                             90.4/9.6  40.6   280                                        HFC-236fa/HFC-254ca                                                                             92.4/7.6  40.8   281                                        HFC-236fa/HFC-254cb                                                                             99.8/0.2  39.4   272                                        HFC-236fa/HFC-254eb                                                                             74.4/25.6 41.5   286                                        HFC-236fa/HFC-272ca                                                                             79.3/20.7 40.6   280                                        HFC-236fa/HFC-272ea                                                                             88.9/11.1 43.2   298                                        HFC-236fa/HFC-281ea                                                                             62.5/37.5 54.0   372                                        HFC-236fa/HFC-281fa                                                                             75.3/24.7 48.4   334                                        ______________________________________                                    

EXAMPLE 2 Impact of Vapor Leakage on Vapor Pressure at 25° C.

A vessel is charged with an initial composition at 25° C., and theinitial vapor pressure of the composition is measured. The compositionis allowed to leak from the vessel, while the temperature is heldconstant at 25° C., until 50 weight percent of the initial compositionis removed, at which time the vapor pressure of the compositionremaining in the vessel is measured. The results are summarized below.

    ______________________________________                                                    INITIAL  50% LEAK   DELTA                                         WT % A/WT % B PSIA    KPA    PSIA  KPA  % P                                   ______________________________________                                        HFC-236ca/HFC-236fa                                                           7.6/92.4      39.5    272    39.5  272  0.0                                   1/99          39.4    272    39.4  272  0.0                                   40/60         37.8    261    37.2  256  1.6                                   60/40         35.4    244    33.6  232  5.1                                   90/20         31.5    217    28.8  199  8.6                                   85/15         30.2    208    27.6  190  8.6                                   99/1          25.4    175    25.1  173  1.2                                   HFC-236ca/HFC-245eb                                                           9.1/90.9      16.9    117    16.9  117  0.0                                   1/99          16.9    117    16.9  117  0.0                                   40/60         17.4    120    17.3  119  0.6                                   60/40         20.     138    19.1  132  4.5                                   85/15         22.5    155    21.4  148  4.9                                   99/1          24.8    171    24.8  171  0.0                                   HFC-236ca/HFC-245fa                                                           98.3/1.7      24.9    172    24.9  172  0.0                                   99/1          24.9    172    24.9  172  0.0                                   60/40         24.4    168    24.3  168  0.4                                   40/60         23.7    163    23.6  163  0.4                                   20/80         22.8    157    22.7  157  0.4                                   1/99          21.7    150    21.7  150  0.0                                   HFC-236ca/HFC-254eb                                                           77.4/22.6     21.7    150    21.7  150  0.0                                   90/10         23.     159    22.5  155  2.2                                   99/1          24.8    171    24.8  171  0.0                                   50/50         25.2    174    23.5  162  6.7                                   45/55         26.1    180    24.2  167  7.3                                   40/60         27.1    187    25.1  173  7.4                                   30/70         29.2    201    27.1  187  7.2                                   20/80         31.1    214    29.5  203  5.1                                   1/99          34.6    239    34.5  238  0.3                                   HFC-236ca/HFC-263ca                                                           35.4/64.6     17.8    123    17.8  123  0.0                                   20/80         17.9    123    17.9  123  0.0                                   1/99          18.2    125    18.2  125  0.0                                   60/40         18.4    127    18.2  125  1.1                                   80/20         20.6    142    19.7  136  4.4                                   90/10         22.7    157    21.7  150  4.4                                   99/1          24.8    171    24.7  170  0.4                                   HFC-236ca/HFC-263fb                                                           13.7/86.3     54.6    376    54.6  376  0.0                                   1/99          54.1    373    54.1  373  0.0                                   40/60         53.1    366    52.   359  2.1                                   60/40         49.8    343    45.4  313  8.8                                   65/35         48.5    334    42.7  294  12.                                   63/37         49.     338    43.8  302  10.6                                  62/38         49.3    340    44.4  306  9.9                                   HFC-236ca/HFC-272ca                                                           46.8/53.2     40.2    277    40.2  277  0.0                                   20/80         38.8    268    37.5  259  3.4                                   1/99          34.9    241    34.6  239  0.9                                   10/90         37.2    256    35.8  247  3.8                                   70/30         39.     269    37.6  259  3.6                                   85/15         35.7    246    31.2  215  12.6                                  82/18         36.7    253    32.8  226  10.6                                  81/19         36.9    254    33.3  230  9.8                                   HFC-236ca/HFC-272fb                                                           56.1/43.9     29.     200    29.   200  0.0                                   30/70         28.4    196    28.2  194  0.7                                   10/90         27.2    188    27.   186  0.7                                   1/99          26.5    183    26.5  183  0.0                                   80/20         28.2    194    27.9  192  1.1                                   99/1          25.2    174    25.1  173  0.4                                   HFC-236ca/HFC-281ea                                                           16.3/83.7     47.4    327    47.4  327  0.0                                   1/99          47.2    325    47.2  325  0.0                                   40/60         46.8    323    46.5  321  0.6                                   60/40         45.     310    43.7  301  2.9                                   80/20         40.6    280    36.1  249  11.1                                  78/22         41.3    285    37.2  256  9.9                                   HFC-236ca/                                                                    HFC-356mmz                                                                    78.1/21.9     25.8    178    25.8  178  0.0                                   90/10         25.6    177    25.5  176  0.4                                   99/1          25.     172    25.   172  0.0                                   50/50         24.9    172    24.3  168  2.4                                   30/70         23.     159    21.4  148  7.                                    20/80         21.6    149    19.5  134  9.7                                   18/82         21.2    146    19.2  132  9.4                                   10/90         19.5    134    17.8  123  8.7                                   1/99          16.9    117    16.7  115  1.2                                   HFC-236cb/HFC-236ea                                                           36.7/63.3     27.6    190    27.6  190  0.0                                   20/80         28.3    195    28.1  194  0.7                                   1/99          29.9    206    29.9  206  0.0                                   60/40         28.7    198    28.4  196  4.5                                   80/20         30.9    213    30.4  210  1.6                                   99/1          33.5    231    33.4  230  0.3                                   HFC-236cb/HFC-236fa                                                           28.2/71.8     41.7    288    41.7  288  0.0                                   15/85         41.3    285    41.2  284  0.2                                   1/99          39.6    273    39.5  272  0.3                                   60/40         40.     276    39.5  272  1.3                                   80/20         37.5    259    36.6  252  2.4                                   99/1          33.8    233    33.8  233  0.0                                   HFC-236cb/HFC-245fa                                                           25.6/74.4     20.5    141    20.5  141  0.0                                   10/90         21.3    147    21.1  145  0.9                                   1/99          21.7    150    21.7  150  0.0                                   60/40         24.4    168    22.7  157  7.                                    65/35         25.4    175    23.5  162  7.5                                   70/30         26.5    183    24.4  168  7.9                                   80/20         28.8    199    26.9  185  6.6                                   99/1          33.4    230    33.2  229  0.6                                   HFC-236cb/HFC-254cb                                                           52.1/47.9     28.8    199    28.8  199  0.0                                   80/20         30.7    212    30.3  209  1.3                                   99/1          33.4    230    33.4  230  0.0                                   20/80         31.7    219    30.9  213  2.5                                   1/99          34.2    236    34.2  236  0.0                                   HFC-236cb/HFC-254eb                                                           39/61         35.2    243    35.2  243  0.0                                   20/80         35.1    242    35.1  242  0.0                                   1/99          34.8    240    34.8  240  0.0                                   70/30         34.8    240    34.8  240  0.0                                   90/10         34.2    236    34.1  235  0.3                                   99/1          33.7    232    33.7  232  0.0                                   HFC-236cb/HFC-263fb                                                           19/81         55.     379    55.   379  0.0                                   10/90         54.8    378    54.8  378  0.0                                   1/99          54.1    373    54.1  373  0.0                                   50/50         53.     365    51.7  356  2.5                                   80/20         45.4    313    41.3  285  9.                                    82/18         44.6    308    40.4  279  9.4                                   84/16         43.7    301    39.5  272  9.6                                   85/15         43.2    298    39.1  270  9.5                                   99/1          34.4    237    33.9  234  1.5                                   HFC-236cb/HFC-272ca                                                           58.2/41.8     41.3    285    41.3  285  0.0                                   80/20         40.     276    39.3  271  1.8                                   99/1          34.2    236    33.9  234  0.9                                   20/80         38.8    268    37.4  258  3.6                                   1/99          34.8    240    34.6  239  0.6                                   HFC-236cb/HFC-272fb                                                           45/55         26.1    180    26.1  180  0.0                                   20/80         26.7    184    26.7  184  0.0                                   1/99          26.7    184    26.5  183  0.7                                   75/25         28.1    194    27.5  190  2.1                                   99/1          33.3    230    33.2  229  0.3                                   HFC-236cb/HFC-281ea                                                           39.1/60.9     48.9    337    48.9  337  0.0                                   20/80         48.5    334    48.4  334  0.2                                   1/99          47.2    325    47.2  325  0.0                                   70/30         47.1    325    46.1  318  2.1                                   85/15         43.5    300    41.1  283  5.5                                   92/8          40.1    276    37.6  259  6.2                                   99/1          34.7    239    34.1  235  1.7                                   HFC-236cb/HFC-281fa                                                           56.1/43.9     40.4    279    40.4  279  0.0                                   80/20         39.2    270    38.8  268  1.                                    99/1          34.1    235    34.   234  0.3                                   20/80         39.1    270    38.9  268  0.5                                   1/99          37.8    261    37.8  261  0.0                                   HFC-236ea/HFC-236fa                                                           17.6/82.4     41.4    285    41.4  285  0.0                                   1/99          39.7    274    39.6  273  0.3                                   40/60         40.2    277    39.6  273  1.5                                   60/40         37.6    259    36.3  250  3.5                                   80/20         34.1    235    32.8  226  3.8                                   99/1          30.1    208    30.0  207  0.3                                   HFC-236ea/HFC-245cb                                                           3.7/96.3      67.6    466    67.6  466  0.0                                   1/99          67.5    465    67.5  465  0.0                                   20/80         65.9    454    64.8  447  1.7                                   40/60         61.1    421    56.3  388  7.9                                   45/55         59.5    410    53.6  370  9.9                                   46/54         59.2    408    53.0  365  10.5                                  HFC-236ea/HFC-263fb                                                           20.0/80.0     56.2    387    56.2  387  0.0                                   1/99          54.3    374    54.2  374  0.2                                   50/50         53.7    370    51.5  355  4.1                                   65/35         50.2    346    45.4  313  9.6                                   66/34         49.9    344    44.9  310  10.0                                  HFC-236ea/HFC-272ca                                                           50.0/50.0     41.7    288    41.7  288  0.0                                   25/75         40.6    280    39.2  270  3.4                                   1/99          35.0    241    34.6  239  1.1                                   75/25         40.0    276    38.7  267  3.2                                   99/1          30.6    211    30.1  208  1.6                                   HFC-236ea/HFC-272fb                                                           75.0/25.0     31.0    214    31.0  214  0.0                                   99/1          30.0    207    29.9  206  0.3                                   40/60         29.9    206    29.6  204  1.0                                   20/80         28.5    197    28.0  193  1.8                                   1/99          26.6    183    26.5  183  0.4                                   HFC-236ea/HFC-281ea                                                           33.9/66.1     48.7    336    48.7  336  0.0                                   15/85         48.2    332    48.1  332  0.2                                   1/99          47.2    325    47.2  325  0.0                                   60/40         47.5    328    46.8  323  1.5                                   80/20         43.7    301    40.5  279  7.3                                   87/13         40.8    281    36.8  254  9.8                                   88/12         40.3    278    36.2  250  10.2                                  HFC-236ea/HFC-281fa                                                           44.8/55.2     39.9    275    39.9  275  0.0                                   20/80         39.2    270    39.0  269  0.5                                   1/99          37.8    261    37.8  261  0.0                                   60/40         39.6    273    39.4  272  0.5                                   80/20         37.4    258    36.4  251  2.7                                   99/1          30.5    210    30.2  208  1.0                                   HFC-236fa/HFC-245ca                                                           98/2          39.5    272    39.5  272  0.0                                   99/1          39.4    272    39.4  272  0.0                                   60/40         32.9    227    27.4  189  16.7                                  70/30         35.4    244    31.5  217  11.                                   72/28         35.8    247    32.4  223  9.5                                   HFC-236fa/HFC-245eb                                                           90.4/9.6      40.6    280    40.6  280  0.0                                   99/1          39.7    274    39.6  273  0.3                                   60/40         37.6    259    34.1  235  9.3                                   59/41         37.5    259    33.7  232  10.1                                  HFC-236fa/HFC-254ca                                                           92.4/7.6      40.8    281    40.8  281  0.0                                   99/1          39.9    275    39.6  273  0.8                                   60/40         36.9    254    30.7  212  16.8                                  70/30         38.7    267    35.6  245  8.                                    67/33         38.3    264    34.3  236  10.4                                  68/32         38.4    265    34.8  240  9.4                                   HFC-236fa/HFC-254cb                                                           99.8/0.2      39.4    272    39.4  272  0.0                                   70/30         38.8    268    38.7  267  0.3                                   40/60         37.3    257    37.1  256  0.5                                   20/80         35.9    248    35.7  246  0.6                                   1/99          34.3    236    34.2  236  0.3                                   HFC-236fa/HFC-254eb                                                           74.4/25.6     41.5    286    41.5  286  0.0                                   90/10         40.9    282    40.7  281  0.5                                   99/1          39.6    273    39.5  272  0.3                                   40/60         39.7    274    39.3  271  1.                                    20/80         37.6    259    37.   255  1.6                                   1/99          34.9    241    34.9  241  0.0                                   HFC-236fa/HFC-272ca                                                           79.3/20.7     40.6    280    40.6  280  0.0                                   90/10         40.3    278    40.3  278  0.0                                   99/1          39.5    272    39.5  272  0.0                                   40/60         38.7    267    38.2  263  1.3                                   20/80         36.9    254    36.3  250  1.6                                   1/99          34.6    239    34.6  239  0.0                                   HFC-236fa/HFC-272ea                                                           88.9/11.1     43.2    298    43.2  298  0.0                                   99/1          40.6    280    39.8  274  2.                                    60/40         39.6    273    34.6  239  12.6                                  65/35         40.6    280    36.9  254  9.1                                   64/36         40.4    279    36.4  251  9.9                                   HFC-236fa/HFC-281ea                                                           62.5/37.5     54.     372    54.   372  0.0                                   80/20         52.8    364    51.7  356  2.1                                   90/10         49.7    343    46.5  321  6.4                                   95/5          46.2    319    42.6  294  7.8                                   99/1          41.2    284    39.9  275  3.2                                   40/60         52.8    364    52.2  360  1.1                                   20/80         50.4    347    49.4  341  2.                                    10/90         48.9    337    48.2  332  1.4                                   1/99          47.3    326    47.2  325  0.2                                   HFC-236fa/HFC-281fa                                                           75.3/24.7     48.4    334    48.4  334  0.0                                   90/10         46.9    323    45.6  314  2.8                                   99/1          40.9    282    39.9  275  2.4                                   40/60         45.2    312    43.3  299  4.2                                   20/80         41.8    288    39.9  275  4.5                                   10/90         39.8    274    38.6  266  3.                                    1/99          37.9    261    37.8  261  0.3                                   ______________________________________                                    

The results of this Example show that these compositions are azeotropicor azeotrope-like because when 50 wt. % of an original composition isremoved, the vapor pressure of the remaining composition is within about10% of the vapor pressure of the original composition, at a temperatureof 25° C.

EXAMPLE 3 Impact of Vapor Leakage at -25° C.

A leak test is performed on compositions of HFC-236fa and HFC-272ea, atthe temperature of -25° C. The results are summarized below.

    ______________________________________                                        WT % A/WT % B INITIAL    50% LEAK   DELTA                                     HFC-236fa/HFC-272ea                                                                         PSIA    KPA    PSIA  KPA  % P                                   ______________________________________                                        87.9/12.1     5.68    39.2   5.68  39.2 0.0                                   99/1          5.27    36.3   5.05  34.8 4.2                                   64/36         5.34    36.8   4.84  33.4 9.4                                   63/37         5.32    36.7   4.78  33.0 10.2                                  ______________________________________                                    

These results show that compositions of HFC-236fa and HFC-272ea areazeotropic or azeotrope-like at different temperatures, but that theweight percents of the components vary as the temperature is changed.

EXAMPLE 4 Refrigerant Performance

The following table shows the performance of various refrigerants. Thedata are based on the following conditions.

Evaporator temperature 48.0° F. (8.9° C.)

Condenser temperature 115.0° F. (46.1° C.)

Subcooled 12.0° F. (6.7° C.)

Return gas 65.0° F. (18.3° C.)

Compressor efficiency is 75%.

The refrigeration capacity is based on a compressor with a fixeddisplacement of 3.5 cubic feet per minute and 75% volumetric efficiency.Capacity is intended to mean the change in enthalpy of the refrigerantin the evaporator per pound of refrigerant circulated, i.e. the heatremoved by the refrigerant in the evaporator per time. Coefficient ofperformance (COP) is intended to mean the ratio of the capacity tocompressor work. It is a measure of refrigerant energy efficiency.

    ______________________________________                                                                                Capacity                                       Evap.    Cond.    Comp. Dis.   BTU/                                  Refrig.  Press.   Press.   Temp. °F.                                                                           min                                   Comp.    Psia(kPa)                                                                              Psia(kPa)                                                                              (°C.)                                                                          COP  (kw)                                  ______________________________________                                        CFC-11   8(55)    30(207)  167(75) 5.10  50(0.9)                              HCFC-22  95(655)  258(1779)                                                                              183(84) 4.60 397(7.0)                              HFC-236ca/                                                                    HFC-236fa                                                                     1.0/99.0 21(145)  69(476)  129(54) 4.71 103(1.8)                              7.6/92.4 21(145)  69(476)  129(54) 4.71 102(1.8)                              95.0/5.0 14(97)   50(345)  134(57) 4.85  77(1.4)                              HFC-236ca/                                                                    HFC-245eb                                                                     1.0/99.0 9(62)    34(234)  139(59) 4.95  53(0.9)                              9.1/90.9 9(62)    35(241)  138(59) 4.95  54(1.0)                              95.0/5.0 14(97)   48(331)  134(57) 4.85  73(1.3)                              HFC-236ca/                                                                    HFC-245fa                                                                     5.0/95.0 12(83)   43(296)  137(58) 4.9   66(1.2)                              98.3/1.7 14(97)   48(331)  134(57) 4.85  74(1.3)                              99.0/1.0 14(97)   49(338)  134(57) 4.85  74(1.3)                              HFC-236ca/                                                                    HFC-254eb                                                                     5.0/95.0 20(138)  64(441)  137(58) 4.85 100(1.8)                              77.4/22.6                                                                              15(103)  53(365)  135(57) 4.86  81(1.4)                              95.0/5.0 14(97)   50(345)  134(57) 4.84  76(1.3)                              HFC-236ca/                                                                    HFC-263ca                                                                     5.0/95.0 10(69)   36(248)  143(62) 4.99  57(1.0)                              35.4/64.6                                                                              11(76)   39(269)  141(61) 4.96  62(1.1)                              95.0/5.0 14(97)   48(331)  135(57) 4.85  73(1.3)                              HFC-236ca/                                                                    HFC-263fb                                                                     5.0/95.0 31(214)  95(655)  137(58) 4.76 145(2.6)                              13.7/86.3                                                                              30(207)  91(627)  137(58) 4.77 139(2.4)                              95.0/5.0 15(103)  51(352)  134(57) 4.87  79(1.4)                              HFC-236ca/                                                                    HFC-272ca                                                                     5.0/95.0 20(138)  63(434)  142(61) 4.92 100(1.8)                              46.8/53.2                                                                              18(124)  59(407)  139(59) 4.96  94(1.7)                              95.0/5.0 14(97)   50(345)  135(57) 4.85  77(1.4)                              HFC-236ca/                                                                    HFC-272fb                                                                     5.0/95.0 15(103)  51(352)  148(64) 4.99  81(1.4)                              56.1/43.9                                                                              15(103)  52(359)  141(61) 4.92  82(1.4)                              95.0/5.0 14(97)   50(345)  135(57) 4.86  76(1.3)                              HFC-236ca/                                                                    HFC-281ea                                                                     5.0/95.0 28(193)  84(579)  147(64) 4.92 135(2.4)                              16.3/83.7                                                                              27(186)  82(565)  146(63) 4.91 132(2.3)                              95.0/5.0 15(103)  53(365)  135(57) 4.88  81(1.4)                              HFC-236ca/                                                                    HFC-                                                                          356mmz                                                                        5.0/95.0 9(62)    34(234)  123(51) 4.78  50(0.9)                              78.1/21.9                                                                              13(90)   45(310)  131(55) 4.83  69(1.2)                              95.0/5.0 14(97)   48(331)  133(56) 4.84  73(1.3)                              HFC-236cb/                                                                    HFC-236ea                                                                     5.0/95.0 16(110)  56(386)  133(56) 4.81  85(1.5)                              36.7/63.3                                                                              17(117)  58(400)  132(56) 4.79  88(1.5)                              95.0/5.0 19(131)  63(434)  130(54) 4.74  95(1.7)                              HFC-236cb/                                                                    HFC-236fa                                                                     5.0/95.0 21(145)  69(476)  129(54) 4.71 103(1.8)                              28.2/71.8                                                                              21(145)  67(462)  129(54) 4.71 100(1.8)                              95.0/5.0 19(131)  64(441)  129(54) 4.74  95(1.7)                              HFC-236cb/                                                                    HFC-245fa                                                                     5.0/95.0 12(83)   43(296)  137(58) 4.9   67(1.2)                              25.6/74.4                                                                              14(97)   47(324)  135(57) 4.89  73(1.3)                              95.0/5.0 19(131)  62(427)  130(54) 4.74  94(1.7)                              HFC-236cb/                                                                    HFC-254cb                                                                     5.0/95.0 20(138)  64(441)  136(58) 4.85  99(1.7)                              52.1/47.9                                                                              20(138)  64(441)  133(56) 4.8   98(1.7)                              95.0/5.0 19(131)  64(441)  130(54) 4.75  96(1.7)                              HFC-236cb/                                                                    HFC-254eb                                                                     5.0/95.0 20(138)  65(448)  136(58) 4.85 101(1.8)                              39.0/61.0                                                                              20(138)  65(448)  134(57) 4.81 100(1.8)                              95.0/5.0 20(138)  64(441)  130(54) 4.75  96(1.7)                              HFC-236cb/                                                                    HFC-263fb                                                                     5.0/95.0 32(221)  96(662)  137(58) 4.76 146(2.6)                              19.0/81.0                                                                              30(207)  93(641)  136(58) 4.76 141(2.5)                              95.0/5.0 20(138)  66(455)  130(54) 4.75  99(1.7)                              HFC-236cb/                                                                    HFC-272ca                                                                     5.0/95.0 20(138)  63(434)  141(61) 4.93 101(1.8)                              58.2/41.8                                                                              21(145)  66(455)  135(57) 4.84 102(1.8)                              95.0/5.0 20(138)  64(441)  130(54) 4.75  97(1.7)                              HFC-236cb/                                                                    HFC-272fb                                                                     5.0/95.0 15(103)  51(352)  147(64) 5     83(1.5)                              45.0/55.0                                                                              18(124)  59(407)  141(61) 4.91  92(1.6)                              95.0/5.0 20(138)  64(441)  130(54) 4.76  96(1.7)                              HFC-236cb/                                                                    HFC-281ea                                                                     5.0/95.0 28(193)  85(586)  147(64) 4.92 136(2.4)                              39.1/60.9                                                                              28(193)  84(579)  142(61) 4.87 133(2.3)                              95.0/5.0 21(145)  67(462)  131(55) 4.76 102(1.8)                              HFC-236cb/                                                                    HFC-281fa                                                                     5.0/95.0 22(152)  70(483)  148(64) 4.94 112(2.0)                              56.1/43.9                                                                              23(159)  73(503)  140(60) 4.86 114(2.0)                              95.0/5.0 20(138)  66(455)  131(55) 4.76 100(1.8)                              HFC-236ea/                                                                    HFC-236fa                                                                     5.0/95.0 21(145)  69(476)  129(54) 4.71 102(1.8)                              17.6/82.4                                                                              21(145)  67(462)  130(54) 4.74 100(1.8)                              95.0/5.0 16(110)  56(386)  133(56) 4.8   85(1.5)                              HFC-236ea/                                                                    HFC-245cb                                                                     1.0/99.0 38(262)  111(765) 124(51) 4.55 159(2.8)                              3.7/96.3 37(255)  109(752) 124(51) 4.56 157(2.8)                              95.0/5.0 17(117)  58(400)  133(56) 4.82  88(1.5)                              HFC-236ea/                                                                    HFC-263fb                                                                     5.0/95.0 32(221)  96(662)  137(58) 4.76 146(2.6)                              20.0/80.0                                                                              29(200)  91(627)  137(58) 4.78 138(2.4)                              95.0/5.0 17(117)  58(400)  134(57) 4.82  89(1.6)                              HFC-236ea/                                                                    HFC-272ca                                                                     5.0/95.0 20(138)  63(434)  141(61) 4.93 101(1.8)                              50.0150.0                                                                              19(131)  61(421)  138(59) 4.89  97(1.7)                              95.0/5.0 17(117)  57(393)  134(57) 4.82  86(1.5)                              HFC-236ea/                                                                    HFC-272fb                                                                     5.0/95.0 15(103)  51(352)  148(64) 4.98  82(1.4)                              75.0/25.0                                                                              17(117)  56(386)  138(59) 4.87  88(1.5)                              95.0/5.0 16(110)  56(386)  134(57) 4.82  86(1.5)                              HFC-236ea/                                                                    HFC-281ea                                                                     5.0/95.0 28(193)  85(586)  147(64) 4.91 135(2.4)                              33.9/66.1                                                                              26(179)  81(558)  145(63) 4.89 128(2.3)                              95.0/5.0 18(124)  59(407)  135(57) 4.84  91(1.6)                              HFC-236ea/                                                                    HFC-281fa                                                                     5.0/95.0 22(152)  70(483)  148(64) 4.95 112(2.0)                              44.8/55.2                                                                              21(145)  69(476)  144(62) 4.91 109(1.9)                              95.0/5.0 17(117)  58(400)  135(57) 4.83  89(1.6)                              HFC-236fa/                                                                    HFC-245ca                                                                     5.0/95.0 8(55)    30(207)  139(59) 5.0   47(0.8)                              98.0/2.0 21(145)  68(469)  129(54) 4.71 101(1.8)                              99.0/1.0 21(145)  69(476)  129(54) 4.71 102(1.8)                              HFC-236fa/                                                                    HFC-245eb                                                                     5.0/95.0 10(69)   35(241)  138(59) 4.96  55(1.0)                              90.4/9.6 20(138)  65(448)  130(54) 4.75  97(1.7)                              99.0/1.0 21(145)  69(476)  129(54) 4.71 103(1.8)                              HFC-236fa/                                                                    HFC-254ca                                                                     5.0/95.0 8(55)    29(200)  142(61) 5.05  46(0.8)                              92.4/7.6 19(131)  64(441)  130(54) 4.75  96(1.7)                              99.0/1.0 21(145)  69(476)  129(54) 4.71 102(1.8)                              HFC-236fa/                                                                    HFC-254cb                                                                     5.0/95.0 20(138)  64(441)  136(58) 4.85 100(1.8)                              99.8/0.2 21(145)  69(476)  129(54) 4.71 103(1.8)                              HFC-236fa/                                                                    HFC-254eb                                                                     5.0/95.0 20(138)  65(448)  136(58) 4.84 101(1.8)                              74.4/25.6                                                                              21(145)  69(476)  131(55) 4.75 104(1.8)                              95.0/5.0 21(145)  69(476)  129(54) 4.72 103(1.8)                              HFC-236fa/                                                                    HFC-272ca                                                                     5.0/95.0 20(138)  64(441)  141(61) 4.92 102(1.8)                              79.3/20.7                                                                              22(152)  70(483)  132(56) 4.78 106(1.9)                              95.0/5.0 22(152)  70(483)  130(54) 4.73 104(1.8)                              HFC-236fa/                                                                    HFC-272ea                                                                     5.0/95.0 12(83)   41(283)  149(65) 5.05  67(1.2)                              88.9/11.1                                                                              21(145)  67(462)  132(56) 4.76 101(1.8)                              95.0/5.0 21(145)  68(469)  130(54) 4.73 102(1.8)                              HFC-236fa/                                                                    HFC-281ea                                                                     5.0/95.0 28(193)  85(586)  147(64) 4.92 136(2.4)                              62.5/37.5                                                                              27(186)  84(579)  138(59) 4.82 130(2.3)                              95.0/5.0 23(159)  73(503)  131(55) 4.73 109(1.9)                              HFC-236fa/                                                                    HFC-281fa                                                                     5.0/95.0 22(152)  70(483)  148(64) 4.95 113(2.0)                              75.3/24.7                                                                              24(165)  76(524)  136(58) 4.79 116(2.0)                              95.0/5.0 22(152)  72(496)  130(54) 4.73 107(1.9)                              ______________________________________                                    

EXAMPLE 5

This Example is directed to measurements of the liquid/vapor equilibriumcurves for the mixtures in FIGS. 1-35.

Turning to FIG. 1, the upper curve represents the composition of theliquid, and the lower curve represents the composition of the vapor.

The data for the compositions of the liquid in Figure I are obtained asfollows. A stainless steel cylinder is evacuated, and a weighed amountof HFC-236ca is added to the cylinder. The cylinder is cooled to reducethe vapor pressure of HFC-236ca, and then a weighed amount of HFC-236fais added to the cylinder. The cylinder is agitated to mix the HFC-236caand HFC-236fa, and then the cylinder is placed in a constant temperaturebath until the temperature comes to equilibrium at 25° C., at which timethe vapor pressure of the HFC-236ca and HFC236fa in the cylinder ismeasured. Additional samples of liquid are measured the same way, andthe results are plotted in FIG. 1.

The curve which shows the composition of the vapor is calculated usingan ideal gas equation of state.

Vapor/liquid equilibrium data are obtained in the same way for themixtures shown in FIGS. 2-35.

The data in FIGS. 1, 3, 6-10, 12 and 15-35 show that at 25° C., thereare ranges of compositions that have vapor pressures higher than thevapor pressures of the pure components of the composition at that sametemperature. As stated earlier, the higher than expected pressures ofthese compositions may result in an unexpected increase in therefrigeration capacity or efficiency of those compositions when comparedto the pure components of the compositions.

The data in FIGS. 2, 4-5, 11 and 13-14 show that at 25° C., there areranges of compositions that have vapor pressures below the vaporpressures of the pure components of the composition at that sametemperature. These minimum boiling compositions are useful inrefrigeration, and may show an improved efficiency when compared to thepure components of the composition.

The novel compositions of this invention, including the azeotropic orazeotrope-like compositions, may be used to produce refrigeration bycondensing the compositions and thereafter evaporating the condensate inthe vicinity of a body to be cooled. The novel compositions may also beused to produce heat by condensing the refrigerant in the vicinity ofthe body to be heated and thereafter evaporating the refrigerant.

In addition to refrigeration applications, the novel constant boiling orsubstantially constant boiling compositions of the invention are alsouseful as aerosol propellants, heat transfer media, gaseous dielectrics,fire extinguishing agents, expansion agents for polyolefins andpolyurethanes and power cycle working fluids.

ADDITIONAL COMPOUNDS

Other components, such as aliphatic hydrocarbons having a boiling pointof -60° to +60° C., hydrofluorocarbonalkanes having a boiling point of-60° to 60° C., hydrofluoropropanes having a boiling point of between-60° to +60° C., hydrocarbon esters having a boiling point between -60°to +60° C., hydrochlorofluorocarbons having a boiling point between -60°to +60° C., hydrofluorocarbons having a boiling point of -60° to +60°C., hydrochlorocarbons having a boiling point between -60° to +60° C.,chlorocarbons and perfluorinated compounds, can be added to theazeotropic or azeotrope-like compositions described above withoutsubstantially changing the properties thereof, including the constantboiling behavior, of the compositions.

Additives such as lubricants, corrosion inhibitors, surfactants,stabilizers, dyes and other appropriate materials may be added to thenovel compositions of the invention for a variety of purposes providesthey do not have an adverse influence on the composition for itsintended application. Preferred lubricants include esters having amolecular weight greater than 250.

We claim:
 1. An azeotropic or azeotrope-like composition consistingessentially of: about 77-99 weight percent 1,1,2,2,3,3-hexafluoropropaneand about 1-23 weight percent 1,1,1,2-tetrafluoropropane wherein saidcomposition has a vapor pressure less than or equal to 24.8 psia whenthe temperature has been adjusted to 25° C.; about 20-99 weight percent1,1,1,2,2,3-hexafluoropropane and about 1-80 weight percent1,1,2,2-tetrafluoropropane wherein said composition has a vapor pressureless than or equal to 33.4 psia when the temperature has been adjustedto 25° C.; about 1-70 weight percent 1,1,1,2,2,3-hexafluoropropane andabout 30-99 weight percent 1,1,1,2-tetrafluoropropane wherein saidcomposition has a vapor pressure greater than 34.8 psia when thetemperature has been adjusted to 25° C.; about 92-99 weight percent1,1,1,3,3,3-hexafluoropropane and about 1-8 weight percent1,2,2,3-tetrafluoropropane wherein said composition has a vapor pressuregreater than or equal to 39.9 psia when the temperature has beenadjusted to 25° C.; about 99.8 weight percent1,1,1,3,3,3-hexafluoropropane and about 0.2 weight percent1,1,2,2-tetrafluoropropane wherein said composition has a vapor pressuregreater than or equal to 272 kPa when the temperature has been adjustedto 25° C.; or about 40-99 weight percent 1,1,1,3,3,3-hexafluoropropaneand about 1-60 weight percent 1,1,1,2-tetrafluoropropane wherein saidcomposition has a vapor pressure greater than or equal to 39.6 psia whenthe temperature has been adjusted to 25° C.
 2. An azeotropic compositionaccording to claim 1 consisting essentially of about 77 weight percent1,1,2,2,3,3-hexafluoropropane and about 23 weight percent1,1,1,2-tetrafluoropropane; about 52 weight percent1,1,1,2,2,3-hexafluoropropane and about 48 weight percent1,1,2,2-tetrafluoropropane; about 39 weight percent1,1,1,2,2,3-hexafluoropropane and about 61 weight percent1,1,1,2-tetrafluoropropane; about 92 weight percent1,1,1,3,3,3-hexafluoropropane and about 8 weight percent1,2,2,3-tetrafluoropropane; about 99.8 weight percent1,1,1,3,3,3-hexafluoropropane and about 0.2 weight percent1,1,2,2-tetrafluoropropane; or about 74 weight percent1,1,1,3,3,3-hexafluoropropane and about 26 weight percent1,1,1,2-tetrafluoropropane.
 3. A process for producing refrigeration,comprising condensing a composition of claim 1 and thereafterevaporating said composition in the vicinity of a body to be cooled. 4.A process for producing heat comprising condensing a composition ofclaim 1 in the vicinity of a body to be heated, and thereafterevaporating said composition.
 5. A process for producing refrigeration,comprising condensing a composition of claim 2 and thereafterevaporating said composition in the vicinity of a body to be cooled. 6.A process for producing heat comprising condensing a composition ofclaim 2 in the vicinity of a body to be heated, and thereafterevaporating said composition.